How to make telegram bot catch media group?

Question

go

I use the tgbotapi library , I write the bot itself in golang. I want to make an echo bot with a simple function: sending exactly the same message as I sent to the bot. But if I send a message of two photos and one video (media group) or three photos at the same time (media group) or four videos at the same time (media group), then the bot throws me each element of the media group separately. How to solve this incident, the problem is in getting a media group, I can’t figure out how to catch and process it? Tell me please

Bot Code

package main

import (
  "log"

  tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api"
)

func main() {
  bot, err := tgbotapi.NewBotAPI("TOKEN")
  if err != nil {
    log.Panic(err)
  }

  log.Printf("Authorized on account %s", bot.Self.UserName)

  u := tgbotapi.NewUpdate(0)
  u.Timeout = 60

  updates, err := bot.GetUpdatesChan(u)
  if err != nil {
    log.Fatal(err)
  }

  for update := range updates {
    switch {
    case update.Message != nil:
      userName := update.Message.From.UserName

      chatID := update.Message.Chat.ID

      log.Printf("[%s] %d", userName, chatID)

      sendMessage(bot, update.Message, chatID)
    }
  }
}

func sendMessage(bot *tgbotapi.BotAPI, message *tgbotapi.Message, chatID int64) {
  var msg tgbotapi.Chattable
  switch {
  case message.Text != "":
    msg = tgbotapi.NewMessage(chatID, message.Text)

  case message.Photo != nil:
    photoArray := *message.Photo
    photoLastIndex := len(photoArray) - 1
    photo := photoArray[photoLastIndex]
    photoMsg := tgbotapi.NewPhotoShare(chatID, photo.FileID)
    photoMsg.Caption = message.Caption
    msg = photoMsg

  case message.Voice != nil:
    msg = tgbotapi.NewVoiceShare(chatID, message.Voice.FileID)

  case message.Sticker != nil:
    msg = tgbotapi.NewStickerShare(chatID, message.Sticker.FileID)

  case message.Animation != nil:
    msg = tgbotapi.NewAnimationShare(chatID, message.Animation.FileID)

  case message.VideoNote != nil:
    msg = tgbotapi.NewVideoNoteShare(chatID, message.VideoNote.Length, message.VideoNote.FileID)

  case message.Video != nil:
    videoMsg := tgbotapi.NewVideoShare(chatID, message.Video.FileID)
    videoMsg.Caption = message.Caption
    msg = videoMsg

  case message.Audio != nil:
    msg = tgbotapi.NewAudioShare(chatID, message.Audio.FileID)

  case message.Document != nil:
    msg = tgbotapi.NewDocumentShare(chatID, message.Document.FileID)

  case message.Location != nil:
    msg = tgbotapi.NewLocation(chatID, message.Location.Latitude, message.Location.Longitude)

  case message.Contact != nil:
    msg = tgbotapi.NewContact(chatID, message.Contact.PhoneNumber, message.Contact.FirstName)

  default:
    msg = tgbotapi.NewMessage(chatID, "Невозможно отправить")
  }

  _, err := bot.Send(msg)
  if err != nil {
    log.Println(err)
  }
}